1. Field of the Invention
The present invention relates to a radiation curable resin, a paint or ink vehicle composition comprising said resin, a conductive or magnetic paint or ink comprising said vehicle composition, a resistor element using said conductive paint or ink and a magnetic recording medium using said magnetic paint or ink in a dried state.
2. Description of the Prior Art
A number of resins, which can be cured by ultraviolet ray, electron beam or the like, have recently been developed and are now commercially available. Compared with the conventional thermo-setting resins, these radiation curable resins harden in an extremely short time and exhibit excellent properties and therefore are in wide use.
However, since many of these resins are esters such as acrylates, methacrylates, allylates and the like, they have poor alkali-resistant and poor solvent-resistant properties compared with usual thermo-setting resins to limit the scope of their application. In addition to this, they have problem of poor heat-resistant property.
Furthermore, these resins are, in general, inferior in their surface hardness, to a phenolic resin or the like which has an excellent surface hardness. In the case wherein the resins are modified to intentionally be increased of their surface hardness, their adhesive property and flexibility would be decreased. Moreover, since the low molecular weight compounds are used, they have drawback in their poor leveling property when they are incorporated into paint. In contrast to this, the phenolic resin has a drawback that it requires a long curing time.
A carbon-resin composition type resistor element has been widely used as a fixed resistor or a variable resistor. Since the conventional resistor element of this type utilizes a thermo-setting resin as its binder resin, a process at high temperature and a long time is required for its manufacturing. Moreover, if the resistor element is laminated on a paper laminated phenolic sheet or the like, there has been a problem that a degradation of the substrate occurs during the thermo-setting process and an improvement therefor has long been awaited.